Apparatus and method for decapsulating packaged integrated circuits

ABSTRACT

A system for decapsulating a portion of an encapsulated integrated circuit that includes copper elements has a container holding an etchant solution, a pump having an inlet port connected to the container holding an etchant solution, and an outlet port, a heat exchanger having an inlet port connected to the pump outlet port, and an outlet port from the heat exchanger, and control circuitry controlling temperature of the etchant to be at or below ambient temperature by controlling temperature of the heat exchanger.

CROSS-REFERENCE TO RELATED DOCUMENTS

The instant application is a continuation application of U.S.application Ser. No. 14/726,880, filed Jun. 1, 2015, issuing as U.S.Pat. No. 9,991,142 on Jun. 5, 2018, which is a divisional application ofU.S. Ser. No. 13/329,735, filed Dec. 19, 2011, issued as U.S. Pat. No.9,059,184 on Jun. 16, 2015, and claims priority to the effective filingdates of the parent applications. All disclosure of the parentapplications is incorporated in the instant application at least byreference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally to decapsulation of plasticpackaged integrated circuit devices and pertains particularly to systemsand methods for application of etchant materials for decapsulation.

2. Discussion of the State of the Art

Integrated circuits (ICs) function as discrete units and a populatedprinted circuit board (PCB) final assembly consists of many differenttypes of ICs placed in close proximity. Such devices are often sourcedand manufactured elsewhere and are packaged into individual segmentswith all of the delicate IC components protected within the individualpackaging. Plastic encapsulation has been employed for years, typicallyutilizing epoxy or other plastic resin materials, which involves moldingthe protective material around the IC device itself, a central portionof lead frame, bonding wires or other connections between the contactpads on the device and the inner lead fingers on the lead frame.

It is clearly desirable that IC failure analysis be performed utilizingnon-destructive testing procedures which leave the entire encapsulatedpackage structure intact. However, visual inspection, testing, failureanalysis and repair of such encapsulated devices most often requirephysical access to the packaged components and to the wire bonds, innerlead fingers and other connection circuitry thereof. In such casesdecapsulation of the package, at least in part, is necessary to allowfor exposure of the circuits of interest from their outer covering,which is a required first step of failure analysis.

Since the advent of IC plastic packaging, several techniques have beendeveloped for removal of the protective material. One such technique,which is mechanical, is to grind the encapsulant back to a point towhere the IC and connections are exposed, or the encapsulant may be cutalong the sides. Another technique is plasma etching which involvesprecise application and causing the ionized particles of the plasma toreact with the encapsulant material at high temperature, and thendraining away the products of the etching process.

The above methods do have disadvantages however. For example, when usingthe mechanical grinding approach, it is difficult to know precisely whento stop the grinding, and physical damage to connections within thepackage is highly possible. Plasma etching, while being very precise, isin many cases prohibitively expensive, and the fine control required canbe cause for a prohibitively lengthy process as well.

Chemical processes that can remove the encapsulant material aregenerally preferred in the art. Chemical etching provides a balance ofprecision and cost effectiveness, and involves precise application of anacidic, heated corrosive substance, for example nitric acid and/orfuming sulfuric acid. The process may involve manual or automated jetapplication of the acid material. Jet etching is a delicate processwhich requires very careful application of the corrosive material.However, although precise and cost effective, the process does also havecertain disadvantages as practiced in current state-of-the-art systems.

Various deficiencies have been encountered in many prior art systems fordecapsulating packaged electronic devices. For example, decapsulationsystems and methods have difficulty in controlling the desired amount ofetching, prevention of damage to the package including interior copperor other metal wires and device metallization, and also the volume ofacids required to perform the process. Further, although the use ofnitric acid and sulfuric acids or mixtures of the two has been quitesuccessfully used for decapsulating packaged ICs using aluminummetallization and gold or aluminum interconnects, this is not the casefor decapsulating devices using the more recent copper metallization forinterconnects. Nitric acid is effective at removing the mold compound ofthe encapsulant, but also removes the upper layer of copper diemetallization and will damage the copper interconnect wires. In thiscase the top interconnect metallization layer is made unavailable forfailure analysis. For example, one important test is the wire-to-padbond test, well-known in the art as the wire pull and ball shear test.This test is performed at the upper metallization layer, and isimpossible in the case of such copper metallization damage as a resultof prior art etching systems and methods. Sulfuric acid presents thesame difficulties.

Further problems exist in prior art systems for decapsulating packagedelectronic devices by etching, in that external auxiliary heaters aretypically used for heating of the etchant, which can cause a lack ofprecise maintenance of a select temperature of the etchant mix, etchhead, and encapsulated electronic device There is also a problem of alack of keeping etchant acid consumption low due to the absence ofefficient etchant recycling processes. A particular slowness of theetching process exists due to the presence of non-reactive materials onthe etch face, and there is inefficient removal of etching debris.

Therefore, what is clearly needed is a system and method fordecapsulating a packaged electronic device which provides for anefficient and economical etching process utilizing new and noveltechniques involving precise temperature control at the etch head,reduced etchant usage through partial etchant recycling, minimal damageto devices that have copper metallization, and faster etching processspeed.

BRIEF SUMMARY OF THE INVENTION

In one embodiment of the invention a system for decapsulating a portionof an encapsulated integrated circuit that includes copper elements isprovided, comprising a container holding an etchant solution, a pumphaving an inlet port connected to the container holding an etchantsolution, and an outlet port, a heat exchanger having an inlet portconnected to the pump outlet port, and an outlet port from the heatexchanger, and control circuitry controlling temperature of the etchantto be at or below ambient temperature by controlling temperature of theheat exchanger.

In one embodiment the etchant solution at or below ambient temperatureis delivered to a surface of the encapsulated integrated circuitenabling decapsulation without damaging the copper elements. Also, inone embodiment the system further comprises an etch head in an etchplate, enabled to support the encapsulated integrated circuit in amanner to expose the encapsulation surface to the etchant delivered, anda safety cover sealable to the etch plate forming an etchant chamber. Inone embodiment the system further comprises a vertically-translatableram enabled to hold the encapsulated integrated circuit to the etchhead. And in one embodiment an etch plate supports a plurality of etchheads such that different specific etch heads are made available to beused to provide for exposure of different areas of encapsulation ondifferent encapsulated integrated circuits.

In one embodiment of the system the vertically-translatable ram isdriven by gas pressure provided by electrically operated valves. In oneembodiment the pump is a diaphragm pump driven by pressurized gas from areservoir. And in one embodiment the etchant solution comprises one orboth of nitric acid and sulphuric acid in a ratio known to minimizedamage to the copper elements of the encapsulated integrated circuit.

In another aspect of the invention a method for decapsulating a portionof an encapsulated integrated circuit that includes copper elements isprovided, comprising urging an etchant solution from a container by apump to a heat exchanger, controlling temperature of the heat exchangerto at or below ambient temperature, and providing the etchant solutionat or below ambient temperature from the heat exchanger to the portionof the encapsulated integrated circuit to be decapsulated.

In one embodiment the method further comprises holding the encapsulatedintegrated circuit in an etch head in an etch plate and providing asafety cover sealable to the etch plate forming an etchant chamber. Inone embodiment the method further comprises moving avertically-translatable ram enabled to hold the encapsulated integratedcircuit to the etch head. In one embodiment the method further comprisesusing a plurality of etch heads to provide for exposure of differentareas of encapsulation on different encapsulated integrated circuits.

In one embodiment the method further comprises driving thevertically-translatable ram by gas pressure. In one embodiment themethod comprises employing a diaphragm pump driven by pressurized gasfrom a reservoir. And in one embodiment the method comprises mixing oneor both of nitric acid and sulphuric acid in the etchant solution in aratio known to minimize damage to the copper elements of theencapsulated integrated circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a decapsulation system which may beused to implement a system and method according to embodiments of theinvention.

FIG. 2 is an enlarged detail view of an etch head assembly and heatexchanger of the decapsulation system of FIG. 1.

FIG. 3 is a plan view of a heat exchanger block of the heat exchanger ofFIG. 2.

FIG. 4 is a cross-section view of the heat exchanger block of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method and automated system fordecapsulating plastic-packaged ICs, achieved using fuming nitric acid,fuming or concentrated sulfuric acid, or a mixture thereof, at acontrolled temperature. Embodiments of the invention pertain moreparticularly to selective application of the etchant or mixture to theencapsulated device, particularly to an epoxy-encased device, in orderto provide access to the device or chip for internal inspection, testand repair without damage to the copper, gold or aluminum wiresconnecting the semiconductor device to the electrical interconnects ofthe package.

The invention has particular application in decapsulation of packaged ICor semiconductor devices which use the more recent copper technology inconnections, electrical interconnects and chip metallization. Thecombination in one embodiment of the invention of a high concentrationof nitric acid and a high concentration of sulfuric acid is particularlyeffective because the ways in which these two acids remove copper aredifferent and counteract each other. Thus, in the proper combination andat the proper temperature the copper is only minimally removed duringthe process of encapsulation mold compound removal. This is betterunderstood with respect to the following description.

FIG. 1 illustrates a decapsulation system which may be used to implementa system and method in accordance with a preferred embodiment of thepresent invention. FIG. 2 illustrates in greater detail an etch plateand etchant heat exchanger assembly in accordance with the system ofFIG. 1, and FIGS. 3 and 4 illustrate an etchant heat exchanger block inaccordance with the heat exchanger assembly of FIG. 2.

In the following detailed description of the present invention, numerousspecific details are set forth in order to provide a thoroughunderstanding of the invention. However, it will be apparent to theskilled artisan that the present invention may be practiced without allof these specific details. In other instances, well-known methods,procedures and components are not described in detail in order to avoidunnecessarily obscuring description of the new and novel aspects of theinvention. Further, references to FIGS. 1-4 may be made alternatively inthe following description.

Referring to FIG. 1, system 1 includes apparatus for selectively etchingan encapsulant of resinous material surrounding an electronic device,and generally comprises an etching assembly 2 including an etch plate 4,etch head 5, a removable cover 3 forming an etching chamber, etchantsolution sources, a diaphragm dispensing pump for deliveringhigh-velocity pulses of liquid transporting etchant from the etchantsources, a heat exchanger 6 for heating and cooling the transportedetchant, conduits for transporting spent etchant to a waste vessel, anda waste heat exchanger for returning spent etchant to near ambienttemperature. General functionality of the above apparatus is providedbelow.

An automated acid system 34 provides for storage of source etchant aswell as waste etchant. Acid system 34 comprises a plurality of sourceacid and waste acid containers. In this example bottles 31 and 32 aresource bottles, and bottle 33 is a waste bottle. In other embodimentsacid system 34 may be equipped with more than two source bottles, aswell as more than one waste bottle, and may also be enhanced with anautomatic diverter valve (not shown) which, after device packagedecapsulation, may feed waste etchant into one or another waste bottlethat is selected automatically based on acid selection or acid mix ratiothat may be programmed into the system. However, a preferred embodimentof the present invention utilizes only one waste etchant vessel as isfurther described below.

Source etchant is transported to the etching portion of the system by apump 29, which is connected to acid system 34 by etchant supply tubes 30and 35, which in this example, are conduits for etchant acids fromsource bottles 31 and 32. Pump 29 in a preferred embodiment is diaphragmdispensing electric pump capable of delivering precise, high-velocitymicro-metered etchant pulses, and is activated by gas pressure,receiving pressurized nitrogen or other gas from a low-pressurereservoir 21 via tube 25.

Pump 29 is capable of selecting between the two source lines 30 and 35for each delivery cycle, allowing for creation of various mix ratiosbetween etchants or delivering only a single selected etchant. Therapid, high-pressure pulse delivery of each quantity of etchant causesmixes to be homogenous by shear mixing in a heat exchanger (detailedfurther below) as well as in an etchant-resistant heat exchanger tube 26which connects between an outflow port of pump 29 and a heat exchangerof the etch head assembly. Shear mixing of the etchant createsturbulence in the etched cavity formed on the exterior surface of thedevice package encapsulant by reaction of the etchant with the resinousencapsulating material. The turbulence provides for removal ofnon-reactive elements of the encapsulating resin from the etch faceresulting in exposure of more of the reactive material, which providesfor faster etching. Pump 29 is also capable of withdrawing etchant fromthe etched cavity to again deliver the etchant with high-velocitypulses. Such partial recycling of the etchant reduces etchant usagewhile maintaining delivery of high-velocity etchant pulses at a highrate of speed.

Pump 29 in one embodiment is enhanced with capability of real-timemixing of etchants within the volume of the pump thus eliminating theneed for a mixing reservoir, and the operator is able to initiate adecapsulation process with only one acid etchant, stop the process andswitch to a second acid or acid mix, or if necessary switch toadditional mix ratios. The operator may thereby be given completeinteractive control of each step of the etching process.

Block 60 represents a control station comprising inputs for an operatorto adjust various variable functions of pump 29, such as selection ofsource bottles for acid, mixture ratio in case of two or more acidsprovided simultaneously, pulse variables, and the like, through controlcabling 61. Such control elements and interfaces may be accomplished inany of several ways known in the art.

System 1 has an etch head assembly 2 including an etch plate 4, etchhead 5 supported by etch plate 4 and a safety cover 3. As is furtherdetailed below with reference to FIGS. 3 and 4, a unique andadvantageous heat exchanger assembly 6 is also incorporated whichprovides a serpentine of etchant-resistant tubing or passages encased inan aluminum block. The aluminum block also comprises electric heatersembedded within, and is in contact with other thermo-electric modulesthat can either heat or cool the aluminum block. An electronic controlmechanism controlled from station 60 through cabling 61 operates theheaters and thermo-electric modules to maintain the aluminum block at aconstant temperature, which may be varied from station 60, and thus thetemperature of the etchant moving through the serpentine tubing. Theneed for an auxiliary external etchant heating sources is thuseliminated. The temperature can be controlled from well below ambienttemperature; i.e., less than 15 degrees C., to well above the boilingpoint of the etchant; i.e., more than 250 degrees C. Spent waste etchantis moved through a waste heat exchanger (see FIG. 1, element 28) whichreturns the spent etchant to near ambient temperature. Although asdescribed above with reference to acid system 34 of FIG. 1 that morethan one waste etchant bottle may be utilized in some other embodiments,a preferred embodiment of the invention uses only a single waste etchantbottle (33) allowed by the waste etchant being returned to near ambienttemperature by waste etchant heat exchanger 28, so as the single wastevessel receives waste etchant of various mix ratios and from etchprocesses run at different temperatures, depending on the requirementsof the etching process application.

Etch head assembly 2 may in some embodiments incorporate a replaceableetch head insert so that the operator may readily exchange inserts fordifferent decapsulation requirements. For example, different etch headsmay be utilized depending on the acid flow required to expose certainportions of the packaged device in the right order, such as early dieand first bond exposure, wherein it is preferable to have a central andconcentric dispersion of heated acid moving across the package surface.Or in other cases, examination of peripheral components or a large diemay be required which would necessitate a peripheral acid flow. Byutilizing exchangeable etch heads the limits of the area of the packagewhich is to be etchant-attacked is greatly expanded.

Safety cover 3 may be attached to etch plate 4 by clamps (not shown) orother secure attachment apparatus known in the art. Safety cover 3 isremovable by a mechanism (not shown) such as a pivot apparatus, forexample, such that access to the encapsulated device package 8 andgasket or seal 7 is provided for positioning on the etch head 5. Whensafety cover 3 is in place a gasket or seal 10 seals cover 3 to etchplate 4 creating a sealed etch chamber 11.

With cover 3 secured in place, a ram nose 9 is driven toward theencapsulated device package 8 by pressurizing chamber 12 which forcesram 13 down against ram return spring 14, thereby securely holdingdevice package 8 to be decapsulated against the top surface of etch head5 and seal 7. Ram nose 9 thereby securely clamps device package 8 toseal 7 creating a seal between seal 7 and etch head 5. FIG. 2illustrates in greater detail the etch head assembly with heat exchangerand related system components and is referenced alternatively in thefollowing description.

The pressurizing of chamber 12 is caused by pressured nitrogen suppliedthrough tube 15 from valve plate 16. An electrically-operated valve 17on valve plate 16, controlled from station 60, activates to allowpressurized nitrogen from nitrogen source 18 to flow through tube 15 inorder to pressurize chamber 12. When valve 17 is not activated thepressure in tube 15 and chamber 12 is vented to the environment. Anadditional electrically-operated valve 19 on valve plate 16 activates toallow pressurized nitrogen to flow from source 18 through tube 20 to alow-pressure reservoir 21. Pressure in reservoir 21 is measured by apressure transducer 23 connected to reservoir 21 by tube 22. Anelectronic control system opens valve 19 to allow for nitrogen flow fromsource 18 to chamber 21 when the measured pressure in chamber 21 dropsbelow a specific pressure and turns valve 19 off when the measuredpressure is above specific but higher pressure. Pressure in reservoir 21is thereby maintained within a specific range that is less than thepressure of the nitrogen source 18. Low pressure reservoir 21 isconnected to etch plate 4 by tube 24 which is ported to chamber 11through a bore in etch plate 4. Etch head 5, being manufactured ofmaterial that is both resistant to high and low temperatures and to allcombinations of acids used in the etching process, is supported by etchplate 4 and device package 8 mountable to etch head 5 as describedabove. Etch head 5 is directly in contact with etchant heat exchangerassembly 6 and possesses passages for communicating fresh etchant fromthe heat exchanger to the device package 8, as well as for communicatingspent waste etchant to waste heat exchanger 28 and ultimately to wastebottle 33 of acid system 34. Etch head 5 has an etchant source passage36 and two spent etchant passages 37 (see FIG. 2). Referring to FIG. 2,etch head 5 is clamped to heat exchanger 45 by a retainer ring 50 andsealed to etch plate 4 by an “0” ring 51.

FIG. 2 provides an enlarged and more detailed view of the etch plate,heat exchanger and etch head assembly and of the decapsulation system ofFIG. 1. Some of the elements shown in FIG. 2 have also been illustratedand previously described in FIG. 1 and their element numbers anddescription have therefore been omitted in the following description toavoid redundancy. The inventors provide FIG. 2 so that the unique andpatentable aspects of the invention can be better illustrated andunderstood.

Etch plate 4 has safety cover 3 in place and sealed to the upper surfaceusing gasket or seal 10 creating etch chamber 11 (FIG. 1). Etch head 5is clamped to a heat exchanger block 45 using retainer ring 50 andsealed to etch plate 4 by “0” ring 51. Packaged device 8 to bedecapsulated is securely held in place with the downward pressure of ramnose 9 (FIG. 1) and sealed to the upper surface of etch head 5 with seal7.

Heat exchanger block 45 has a central bore 56 which accommodates passageof source etchant from a serpentine heat exchanger tube 40 embeddedwithin heat exchanger block 45, to etchant source passage 36 of etchhead 5. An extension of heat exchanger tube 40 passes up through centralbore 56 and has a flange 42 at the upper end and is sealed to etch head5 communicating with source passage 36 of etch head 5 and sealed by “O”ring 41. Heat exchanger block 45 also has a pair of bores 52 whichaccommodate waste tubes 43 for passage of waste etchant from wastepassages 37 of etch head 5.

Referring back to FIG. 1, pump 29 transports etchant from source bottles31 and/or 32 through supply tubes 30 and 35 to the heat exchanger tube26 which communicates with the serpentine heat exchanger tube 40embedded within heat exchange block 45. In the heat exchanger assembly,the source etchant assumes a temperature near to that of heat exchanger6. This temperature is monitored and controlled from electronic controlstation 60 at the desired value, which may be lower than ambient, suchas 10 degrees C., for decapsulating packaged devices utilizing copperinterconnect wires or copper metallization on the chip. The temperaturemay also be maintained above the boiling point of the etchant, such as250 degrees C., for decapsulating devices that do not contain copper orother such sensitive materials.

Each delivery of a volume of etchant agitates the etchant in contactwith the packaged device 8 and forces some portion of the etchantcontained in the cavity etched into device 8 into the waste passages 37in etch head 5. Waste passages 37 are sealed to the flanges on the endof the waste tubes 43 by “0” rings 38. The waste etchant passes throughetch head 5 into waste tubes 43 and waste junction 44 where the flowfrom both tubes is combined and passes into waste tube 27 (FIG. 1).Waste tube 27 is clamped into a finned heat exchanger 28 (FIG. 1) whichreturns the waste etchant to near ambient temperature, and the wasteetchant may then be transported to waste bottle 33 (FIG. 1) via wastetube 52.

FIG. 3 is a plan view of heat exchanger block 45 of the heat exchangerof FIG. 2 showing the arrangement of internal passages. Bores 52 passthrough block 45 and accommodate passage of waste tubes 43 (FIG. 2).Block 45 also has a central bore 56 which accommodates passage of sourceetchant to etch head 5 through an extension of serpentine heat exchangertube 40 (FIG. 2). A spiral groove 53 is machined into the face of block45 and is designed to accommodate serpentine heat exchanger tube 40(FIG. 2). Tube 40 has an inlet 57 which communicates with heat exchangertube 26 leading from an outflow fitting of pump 29 (FIG. 2).

FIG. 4 is a cross-section view of the heat exchanger block of FIG. 3. Inthis view spiral grooves 53 are shown extending in from the surface ofblock 45. Cross drillings 54 extend through block 45 and accommodateelectric heating elements 58 therein, as is detailed further below. Heatexchanger block 45 has an upper face 55 which in practice of theinvention is directly in contact with etch head 5, as shown in FIG. 2.

Heat exchanger block 45 in manufactured in a preferred embodiment ofaluminum, and in practice of the invention, is fitted with a pair ofelectric heating elements 58 that are placed within cross drillings 54.Source etchant passes from pump 29 (FIG. 1) through heat exchanger tube26 which also extends through heat exchanger block 45 by being placedwithin spiral grooves 53 (FIGS. 3, 4) machined into the face of block45. A cover plate 46 clamps tube 26 into place (FIG. 1). As tube 26 isin direct contact with heat exchanger block 45 and cover 46, there issignificant heat transfer through the wall of heat exchanger tube 26 tothe etchant passing through tube 26.

Referring now back to FIG. 2, opposite to the heat exchanger block andbeneath and in direct contact with cover 46 are a pair of thermoelectricassemblies 47 each of which, when activated by an electronic controlsystem will transfer heat from cover 46 to a heat sink assemblycomprised of a plate 48 and a plurality of fin plates 49 by a processwell known to those skilled in the art. An airflow provided by anelectrically-operated fan (not shown) is directed across the numerousfin plates thereby cooling the fin plates to near ambient temperature.By controlling the level of electrical activation of the thermoelectricassemblies 47, the electronic control system (not shown) can control thetemperature of the heat exchanger block 45 and cover 46 at a level wellbelow ambient temperature.

As the etch head 5 is directly in contact with the upper face 55 of theheat exchanger block 45, the etch head 5 and etchant are at nearly thesame temperature as the heat exchanger block 45 and cover 46. Byactivating the electric heating elements 58 which are placed withincross drillings 54 of FIG. 4, the temperature of the heat exchangerblock 45, cover 46, etch head 5 and the etchant itself can all be raisedcollectively above ambient temperature. The temperature is monitored bythe electronic control system and the power to activate the electricheating elements 58 within cross drillings 54 of heat exchanger block 45is adjusted to maintain the desired temperature. If the temperature ofthe heat exchanger block 45 is above the desired process temperature,the electric heating elements 58 are automatically turned off and thethermoelectric elements 47 are activated. If the temperature of the heatexchanger block 45 is below the desired process temperature, thethermoelectric heating elements 47 are turned off and the electricheating elements 58 are turned on. In the present invention theelectronic control system is a proportional integral derivativecontroller (PID controller); however, other control systems may be usedwithout departing from the scope and spirit of the invention.

In the foregoing specification, the invention has been described withreference to specific embodiments. However, one of ordinary skill in theart will appreciate that various modifications and changes can be madewithout departing from the scope of the present invention as set forthin the claims below. Accordingly, the specification and figures are tobe regarded in an illustrative manner rather than a restrictive case,and all such modifications are intended to be included within the scopeof the invention.

Benefits, other advantages and solutions to problems have been describedabove with regard to specific embodiments. However, the benefits,advantages, solutions to problems and any other element(s) that maycause any benefit, advantage or solution to occur or become morepronounced are not to be construed as critical, required or essentialfeatures or elements of any or all of the claims. As used herein, theterms “comprises”, “comprising” or any variation thereof, are intendedto cover non-exclusive inclusion, such that a process, method, articleor apparatus that comprises a list of elements does not include onlythose elements but may include other elements not expressly listed orinherent to such processes, method, article or apparatus.

Thus, the scope of the present disclosure is to be determined by thebroadest permissible interpretation to the maximum extent allowed bylaw, of the following claims, and shall not be restricted or limited bythe foregoing detailed description.

What is claimed is:
 1. A system for decapsulating a portion of anencapsulated integrated circuit that includes copper elements,comprising: a container holding an etchant solution; a pump having aninlet port connected to the container holding an etchant solution, andan outlet port; a heat exchanger block having an inlet port connected tothe pump outlet port, and an outlet port from the heat exchanger blockdelivering etchant from the pump to the encapsulated integrate circuitthat includes copper elements; and a heat sink assembly having finplates coupled to the heat exchanger block; wherein airflow directedover the fin plates dissipates heat drawn from the heat exchanger block,lowering temperature of the heat exchanger block, and therefore theetchant delivered to the encapsulated integrate circuit that includescopper elements, to at or below ambient temperature.
 2. The system ofclaim 1 wherein the etchant solution at or below the ambient temperatureis delivered to a surface of the encapsulated integrated circuitenabling decapsulation without damaging the copper elements.
 3. Thesystem of claim 1 further comprising an etch head in an etch plate,enabled to support the encapsulated integrated circuit in a manner toexpose the encapsulation surface to the etchant delivered, and a safetycover sealable to the etch plate forming an etchant chamber.
 4. Thesystem of claim 3 further comprising a vertically-translatable ramenabled to hold the encapsulated integrated circuit to the etch head. 5.The system of claim 4 wherein an etch plate supports a plurality of etchheads such that different specific etch heads are made available to beused to provide for exposure of different areas of encapsulation ondifferent encapsulated integrated circuits.
 6. The system of claim 5wherein the vertically-translatable ram is driven by gas pressureprovided by electrically operated valves.
 7. The system of claim 1wherein the pump is a diaphragm pump driven by pressurized gas from areservoir.
 8. The system of claim 1 wherein the etchant solutioncomprises one or both of nitric acid and sulphuric acid in a ratio knownto minimize damage to the copper elements of the encapsulated integratedcircuit.